Engine/Transmission (1998.5 - 2002) Modifying fuel system so temperature input to VP44, 80* - 100*, your inputs.

[rweis]

I went back to my spreadsheet on fuel milage to see over time if there was a difference with cooler fuel. This is hand calculated actual fuel receipts mpg per tankfull.



Towing 13k 5er there is a +1 mpg (2 tanks (about 50 gallons)) 14. 0 mpg



Empty there is a +1 mpg (4 tanks (about 100 gallons)) 18. 4 mpg



Over 62,000 (3 years) 1 mpg diference (empty) would be about 200 gallons. Not a lot of difference, but it is a side benefit not the primary objective.



Bob Weis

 

[keimmmo]

With my relocated fuel filter and cooler, my ecomony is up about 1 mpg towing and close to 2 mpg empty. Since I drive about 35,000 a year, that is significant! Actually, improved fuel ecomony way MY primary goal with improved VP life a secondary goal.



I also see less... as in absolutely NO smoke with the cooler.



I still do not understand all the reasons for the improvements, but I sure like them!



Steve Keim

 

[LLewandowski]

I've read this thread over the last couple days , phew its a long one . Lots of great information . I think this thread is a big help towards my goal , thx for all the info .



I'm converting my 02' cummins to run on WVO (waste veggy oil) . So im actually going to be heating the oil to 160ish before it hits the VP44 . Obviously cooling the fuel isn't an option for me .



I liked the idea earlier in the thread about those little AC 12v heat sinks and have been brainstorming somthing like that for the electronics . Use it to maybe attempt to keep a nice steady cooler temp on the electronics with maybe a t-stat that will allow to run anytime .



Here is a picture of the pump I thought might be helpful . I know that pic dosen't have near enough info , but dosn't it almost look as if the electronics are seperate connected with a wire harness? Maybe it wouldn't be impossable to move it , or even raise it with a good insulator . I took an asbestos abaitment class years ago and remember that its one of the best insulators known .



http://www.veggiediesel.co.uk/ (select pump identification)



I'm very curious about the whole Fedex thing . Bosch must have done tons of studies and research to develope that 'improved pump' . Does anyone know where one could find this info , or an adress for cummins support?





In any case it will be at least a few months before I'm done , but maybe some data from my setup could help you guys and vise versa .

 

[rweis]

IF I were serious about running WVO full time (and that thought has crossed my mind), I would go to Scheids and get them to change the VP44 to a P7100 that is cooled by engine oil. I would be concerned with heating the WVO then expecting it to cool the VP44. I think the fuel temp limits on input is 160* (a Bosch limit).



You get totally away from the Vp44 electronics etc and have an old reliable mechanical pump. Not fancy, but if I remember correctly there are a few TDR members running WVO through the P7100. I think the P7100 can develop decent hp (300 hp?) without trying to run it to the maximum limit.



I have NO IDEA what the conversion does to anything else other than the fuel injection / injector system (requires a change of injectors?, maybe so) nor to the ECM system, APPS system, and who knows what else. I doubt it would be cost effective to make the change, just piece of mind of reliability.



Reliability is what this thread is all about, trying to find it for the VP44.



Bob Weis



aside: As long as I am writing, I think I have found a new twist (maybe).



I have been getting my OAT air intake to the return fuel cooler under my running board and can't figuer out why I get a 5* temp rise as the engine gets to operating temp. I'm thinking it might be the tunnel effect of air off the back of the engine firewall down under the chassis and being picked up by the blowers as input air. I'm going to try to get blower input air from somewhere else to insure I am not getting "tunnel air that has been warmed by the engine". This also applies to any rear mounted coolers under the truck bed. (like mine )

 

[LLewandowski]

I don't think a pump change is possable .



No other systems will be effected , other than me eventually getting some high preformance mods . Reliability is why I'm reading , your stuck with me . :-laf

 

[darkhorse]

I know of at least one TDR member who swapped out his VP44 for a P-pump. It's pretty involved but is possible. I worked with Greasel.com about doing a SVO conversion. After they tested their '01 they wouldn't recommend using the VP44. It was electrical problems that killed their pump.

 

[rweis]

I am finding that there is a latent heat in the "tunnel" under the truck.



Something like a transmission cooler (150* - 225*?) works well because the between frame rail air temps seem to be about 5* - 10* higher than OAT. I have measured it with the engine cold and the BTF (between the frame) temps are OAT. As the engine comes up to temp the heat is passed down under the truck and the BTF temps rise.



Therefore my coolers back under the bed are only getting the fuel down to OAT + 5* - 10*. Sooooooo, any coolers you want to get below / close to OAT need to be up front, or at least not BTF.



The VP44 temp added to the fuel seems to be based solely on rpm. At 1400 it seems to be 3* - 5*. Each 100 rpm above seems to add about 1* or so. 1800 was about 8* - 10*.



At 80* OAT the fuel input is running about 88*, the EBC about 90* and the return fuel about 95* at 1400 rpm.



---------------------------------------

I took off the 4" ducting and the ducted fan off the return coolers because the hotter engine air discharge was warming the return fuel instead of cooling it. The ducting was concentrating the engine discharge heat into the "coolers". Not good.

---------------------------------------



So right now the configuration is:

Home built tube cooler in front of the A/C evaporator,



No OEM ff,



Inline ff wrapped in thermal batting on front crossmember mounted under the fan shroud,



RASP,



RACOR 690T,



H7B (w/ fan right now) in drivers side bed pocket (needing to be moved up front),



2 Deralie frame fuel coolers on outside of drivers side frame not in ducting (needing to be moved up front),



VP return line after the engine T now AN-6 and returned to the tank vent line via the frame fuel coolers,



VP wrapped in thermal blanket,



VP return line to engine T wrapped in thermal balnket,



230 cfm blower connected to ignition circuit and runs 128 minutes after shutdown (post shutdown VP EBC only rises about 5* from VP EBC runnning temp and cools down to OAT before blower stops). The blower gets air from behind the front bumper on drivers side.



So far VP EBC holds at fuel input temp + about 2*. Remains to be seen how the warmer OAT temps will play with the whole thing.



One lesson so far is get good clean cool air to cool with if the attempted temperatures are close to OAT (ie the transmission cooler does fine with OAT +10* since it is cooling 200* transmission fluid).



Bob Weis

 

[rweis]

GOOD idea or BAD idea?



Remove the long weatherstrip off the cab lip to hood compression fitting area so hot engine compartment air can exit there. I remember something about the weatherstrip was to keep water out of the engine compartment. That area still seems to have a verticle lip that should do that.



Ideas?



Bob Weis

 

[RClark]

Wouldn't that let all that hot air enter the vent system and heat up the cab?

i think the parts under the hood are meant to withstand hotter temperatures than we are.

 

[rweis]

Towing update:



Exactely as expected. Fuel is OAT +10* at 1400 rpm EBC is OAT +(10* - 12*) at 1400 rpm.



I intentionally towed at 2400 rpm (60 mph O/D out) for 2 hours. 1* / 100 rpm above 1400 rpm was dead on. At 2400 rpm the EBC was OAT + 20* (1000 rpm above 1400 = 10* additional based on work being done in the VP44).



The fuel temp stayed at OAT +10 which means I have enough cooling being done to take care of the additional heat being generated in the VP44 by the higher rpm. But even at the higher rpm which heated up the EBC, and the cooler fuel flowing under it, the EBC still had a heat rise of 10*.



I guess the "all in all" is that you can keep the EBC within 20* of the OAT which even in the desert SW of 110* OAT should not go much above 130*.



You can keep fuel at OAT +10* cooling the VP44 at no more than 120* body temperature which should be ok for the VP44.



The key is to get your fuel temp to some reasonable value. If you do not know what yours is, tape a thermometer to the ff case should be close enough. If it is high (OAT + 30+) then you have to decide if another 20* above that is ok or not ok for the survivability of the VP44, which is what the objective of the thread is all about anyway.



There are other factors, water, particulate, taping the wire, heat soak, are things that should also be considered.



------------------------

Thanks to Gary for figuering out the post engine shutdown time delay. OAT blowing on the VP44 post shutdown (for 2 hours) will keep the EBC from going much more that an additional 10* above the VP44 shutdown temp.



This is the ttt at the beginning of the summer 2006 and I will ttt this at the end of the summer 2006 and report observations then.



About have this figuered out,



I think



Bob Weis



Oh, BTW, removing the firewall weatherstrip did not seem to change under the hood temperatures much if at all. Ah well.

 

[rweis]

Well we have had some 95* OAT days here in FL. At 95* OAT, fuel input temp becomes ~ 105*, EBC becomes ~ 108*, this is at 1400 rpm (51 mph). At 1800 rpm (60 mph) add 4* more (112*). Not bad, but not where I wanted it, so on to the next temperature control experiment.



There are some threads about using water to cool heat exchangers. Generally the radiator / intercooler area. Discussion gets to the crusty mess left by the water (even distilled clean water because of the road dirt) when it hits the HOT radiator / intercooler / engine.



Since I have a H7B back up in the driver's side rear wheel well I am going to try a version of water cooling - high pressure misting.



My H7B has a fan on it that draws from the wheel well and blows through the H7B out into the "tunnel" between the frame rails. I am going to mount 2 or 3, 1/2 gph 40 - 100 psi misters on the wheel well side of the fan and let the fan blades pull the mist through the fan and push it on through the H7B.



The high pressure misters are advertised to NOT leave a residue of water because of the evaporation and extremely small size dropplet.



I am going to use a Shurflo 8000-543-250 BYPASS pump so there is NOT a constant on / off of a pressure switch (because 1 1/2 gph is not a lot of fluid). The bypass is set at 45 psi so I think it will run the misters very well.



It will be easy to compare the with and without misters in the fuel input temperature since that is monitored full time anyway.



Monitoring the fuel input temp over several months now, I find the VP EBC is about 0* - 3* higher than the input fuel temp (at 1400 rpm). I want to reduce the fuel input temp significantly and see if the VP44 EBC follows in the same 0* - 3* higher temperature characteristic at much lower fuel input temps (maybe OAT - 10*).



One thing that is driving me toward this idea is I got stuck in heavy traffic for several hours a month ago and the active cooler (H7B w/fan) and the passive coolers (frontal copper tubing, and frame mount fuel coolers (no fan on either) I have could not keep the input fuel temp from constantly rising (ie the fan on the H7B could not get the heat generated by the VP44 and the engine from the input fuel temperature from gradually climbing to 140* when we finally got out of the traffic snarl). Hence I am going to try to get more fuel heat out than is generated when stopped in traffic over a long time (hours).



A spin off, depending on how successful the test is in terms of how fine a mist is generated and how it evaporates and how well it cools, might be able to extrapolate VERY LIGHT misting to the radiator frontal area and the cooling that would provide the radiator, intercooler, evaporator system. I stress LIGHT because of the water scale development problem. Maybe there is a combination of very light misting (1/2 gph?) that would be light enough to be totally evaporated before it contacted anything really hot like the intercooler, but would be effective enough in reducing temperatures in a practical way.



Anyway, just a direction I am going to experiment with.



I'll post results when I have some good data in a couple of months.



Bob Weis

 

[PRout]

With this thread in mind, I mounted a Frantz fuel filter under the truck for 2 reasons. Better filtering & some fuel cooling.



Went for a 2 hour drive on the freeway and then checked the temp of the frantz to see how warm it was. I would guess about 100 degrees max. This was after leaving the pump run for about a minute after parking so to make sure it is was close to the temp of the fuel sitting in the tank.



So I guess what im wondering is, is the fuel really getting that hot, or are the 4 metal fuel canisters in the system providing significant cooling? (Water separator & filter on Fass, Frantz, & OEM filter unit under hood).



Was thinking if the frantz were to show hot fuel, then could add one of their cooling units that is basically a heat sink with fins that mount around the metal canister. Not sure how much it would help, but if heat really is an issue it wouldn't hurt.



(Thanks to Gary for his excellent Frantz fuel filter thread - for the idea. )

 

[PRout]

Hmmm... I wonder how much difference it would make installing these around the Fass canisters and the frantz.



http://cool-collar.com/products.htm

 

[rweis]

In one of my passive fuel coolers I have something similar.



Mine is a finned tube about 3" diameter & 18" long and has end plates for fittings. I find that it cools about 2* - 3* from one end to the other.



edit: It is mounted on the drivers side under the bed on a running board support strut and fully exposed to free air flow (when moving).



Definitely does some cooling, but no the total I am trying to accomplish. Might have the same problem if no airflow , stuck in traffic for an hour. Then it might actually heat the fuel from latent engine heat if there is no airflow from the outside (what I found out where I had this particular cooler up under the radiator air flow on the frame. Air flow, temp reduction, no air flow, temp addition).



One of the reasons I am going to try super fine 55um mist (45 psi) is I can easily extend the mist line instead of adding multiple fans. I am getting the tank (21 gallons) 12" x 12" x 31" with LARGE 7" diameter fill cap (so I can get my arm into the tank and wash it out really well), shurflo 8000-543-250 demand pump (continuous run rating), and the DIG Corp MNW misters (40 - 80 psi, 55 um, 1/8 npt, . 6 gph ($1. 55), also need MNTA 1/2" PVC reducing Tee ($. 90), to get the mister hooked up to a 1/2" PVC line. You need a 200 mesh filter to protect the mister from trash in the tank ($17. 50).



My thought is to mist the H7B w/fan cooler so the fan will blow the mist through the H7B easily. Then if the concept is valid extend the misting to the frame rail passive coolers. If the concept is still valid, then extemd the misting to the OEM transmission cooler up front. If the concept is still valid, mist the OEM intercooler / radiator.



The small dropplet (55um) size is important I think. The marketing hype is the mist is so small it evaporates and cools the air, NOT the object (ie the scale accumulation problem might be avoidable). I will use demineralized water as supper clean as possible and probably with some "lime away" mixed in to be sure of no scale.



If the misting is valid, then the fuel cooling is solved, then the VP44 life expectancy (assuming you have clean fuel and not otherwise beating up the VP44) is extended.



As a side benefit of misting is you can mist anything else mearly by extending the mist line, ie no additional fan cost or wiring relay setups.



Interesting ideas might be to leave the OEM ff in place and mist it, mist the VP44 body directly, mist the transmission valve body directly, the differential pumpkin, just a lot of other possibilities. During winter for the northern guys, run some antifreeze in the line and shutoff the pump for the winter.



Just some ideas. If anyone has any input to this idea please chime in. The more discussion the better. Negative inputs especially welcome as they are the most challenging for the concept process.



Bob Weis

 

[Gary - K7GLD]

Hmmm... I wonder how much difference it would make installing these around the Fass canisters and the frantz.



http://cool-collar.com/products.htm

I tried one of the Frantz finned coolers on both my oil bypass and fuel filter - both filters are mounted underhood:



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and I couldn't measure any temp inprovement - perhaps it would work better if mounted where outside airflow is stronger and cooler.

 

[NoSeeUm]

Reading about 25% of this thread (ran out of coffee ) and its all good stuff. I have to work through the rest of it later, its almost as big as the Smarty thread.



Fuel suppy is my next project. Just ordered the Vulcun Kit as a starter source for parts.



Any one tried a installing a seperate cooling circuit on the fuel tank? I mean like using a separate electric pump with a fanned cooler just re-circing the tank.



Jim

 

[rweis]

Jim,



What I think are the problems so far. With respect to fuel heat:



1. Fuel return to the tank pickup canister is a BAD idea, recirculates generated heat - which sort of comes under your thoughts of recirc cooling the tank fuel mass.

2. The VP EBC runs about 3* - 5* above fuel input temp.

3. The VP EBC temp is almost linear with RPM's. I baseline mine @ 1400 rpm @ 51 1/2 mph. Every 100 rpms = 1* in EBC temp.

4. VP after shutdown heat, but that is another story.



Some of the experiments I am doing are sort of tank recirculation ideas on input or return lines just not dedicated to the tank.



However, the tank recirculation cooler could be a better idea than I have come up with so far. The more ideas and testing we can do the better.



My parts, misters, pump, tank have arrived and I am going to try mist cooling some of the fuel coolers and see what that does. What temp drop does it provide?, how bad is the cooler clogging?, what fluid volume does it take? Is one cooler design (fins, flat plate, cylindrical) better with misting than others?.



My wife says I drive a mobile field laboratory rather than a truck. She was not surprised when the tank, pump, mister nozzles, tubing showed up.



I did get her a Mother's day present NOT related to the truck.



Bob Weis

 

[Gary - K7GLD]

On a side note, earlier in this thread I mentioned my use of some aluminum foil as a heat shield/barrier between the engine block and the VP-44, to reduce heat soak on engine shutdown.



That effort seemed to provide measurable improvement, but the installation was poor due to difficulty in properly inserting the foil between the VP-44 and the block with all the other stuff in the way.



I overcame that difficulty the hard way today, when I had to replace my VP-44 because it kept generating P0216 error codes - it ran well, but the codes couldn't be ignored with a 2000 mile RV trip coming up in 10 days or so.



SOOooo, I took time during the VP swap to do the foil blanket bit properly:



-



And now I'll run some more temp runs to get a better idea of the effect...



OH, and that funny black cube is a toroid RF interference filter on the wire tap to the pump for my Edge Comp due to the high power mobile Amateur Radio setup I run in my truck...

 

[Gary - K7GLD]

Announcing!

... The END of my temperature stabilization campaign for the VP-44! (I think... ) :-laf



Earlier in this thread, I displayed a PC CPU heatsink I bought and planned to use mounted on top of my VP-44:

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AND, in the post just above this one, I showed the aluminum foil heat barrier I installed between my new VP-44 and the engine block.



I have also mentioned the revision I had planned with a larger Marine bilge blower to draw in cooler outside airflow direct to the VP-44.



It's all been done, it all WORKS, and *my* quest for stable VP-44 temperature is OVER! (I think... )



Here's the new blower and duct installed on the truck frame between the inner fender well and frame:



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Here's the other end up at the top area of the VP-44:



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And here's the finished installation after the APPS cover is installed:



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SO, how does it work?





Well, with the wimpier PC-type cooling fan I had been using, normal down the road temp rise of the VP-44 was a good 15+ degrees - and then on shutdown, another 20-30 degrees rise due to underhood heatsoak.



The new setup?



A max of 7 degrees rise above ambient, and that temp IMMEDIETLY begins to DROP after engine shutdown, and after about 5 minutes, looks like this:



-



(the TOP reading is ambient - bottom is VP-44)



In another 10 minutes or so, the VP-44 was at exactly ambient temperature...



OH - and by the way, that same airflow helping the VP-44 is ALSO giving some help to the APPS directly above - which has proved to be another sensitive component in our trucks - 2 for the price of 1!



Not TOO shabby for an "armchair mechanic"...



Mission accomplished! Oo. Oo. Oo.

 

[Texas Diesel]

As others have pointed out before, cooling the CASE of the VP is about as effective as putting a cooler on your computer outside case and trying to cool the CPU.



There is no connection, cooling the case does not mean the PC board is cooler.



What you are doing is like trying to cool the engine by blowing air across the valve cover. Even if you read cooler CASE temps, you have failed to prove that that is having any effect on INTERNAL temps.



The thermal mass of the (hot) engine is exponentially greater than your heat sink mounted to the case of the VP.



All the temp readings you posted are from the CASE (like the computer case) not the internal PC board temps.



Comments?